Not responding - too much text in text box

I copied and pasted approx. 300,000 cells of data into a spreadsheet, no issues. I then went to edit a textbox within the same file and accidently posted the 300,000 cells of data into the textbox. This volume of text into the textbox has caused the file to go into a 'Not Responding' spiral. I can wait about half an hour for the file to start responding again, but then I'll try to select the textbox to delete it and end up with a 'Not Responding' greyed out file again.

I have tried force closing the file through task manager and opening it up again a few times but no luck.

Any tips on how I can remove the large amount of erroneous text in the textbox and get my file to work again?

Hi, this unfortunately is not possible and would not help anyone answer. The file is as mentioned, not responding. There is too much text in a textbox, not a cell, which is causing the issue. Even if I did manage to attach it, I assume someone else would then experience the same issue.
Furthermore, my query is not related to any formula errors, so sharing the file will not help anyone be able to answer anymore than reading my description of the issue.